1. Field of the Invention
The present invention is related to an adjustable book shelf which is provided with a plurality of contiguous limiting arms disposed side by side with each other and pivotably mounted to one of a number of telescopic rod members which are removably and adjustably secured between a pair of side boards; and each limiting arm is spring biased and can be pushed to pivot away by an inserted book or books which can then be held in position by the other neighboring limiting arms of the book shelf. A number of spare limiting arms are available so that when the telescopic rod members are extended the same can be attached thereto in addition.
2. Description of the Prior Art
Referring to FIG. 1, the first type book shelf of the prior art is made up of a pair of L shaped side holding hands 1A which are free to move by a person so that the number of books disposed therebetween can be theorically unlimited as long as the side holding hands 1A are able to be located freely on a horizontal plane. However, this type of book shelf has no fixed structure so that the side holding hands are easily pushed aside with the books therebetween collapsed; besides, it is relatively inconvenient in practical use, for instance, if one book is taken away from the shelf, the other books have to be relocated with the side holding hands 1A pushed inwardly toward the center to support the other books in place.
As shown in FIG. 2, the other kind of prior art book shelf is commonly seen and used. This book shelf is characterized in that it is additionally equipped with a slidable U shaped limiting element 32A which is slidably mounted on a pair of grooved tracks 31A defined on the supporting stick 3A of the book shelf. The book shelf has a pair of side boards 2A which are fixedly secured in place and books are held by the slidable limiting element 32A. This type of book shelf is comparatively convenient to operate, but can still be improved in the structure thereof so as to accommodate more books with the books secured more readily in place without manually actuating the sliable holding element 32A.
To make an improvement on the prior book shelves, the present inventor has worked out a new adjustable book shelf which is equipped with a length variable structure and a plurality of pivotably operated and spring biased limiting arms which are contiguously disposed side by side so as to permit the inserted books instantly held in place without making any adjustment on the book shelf or books.